Tamping device for compacting soil, concrete, and the like

ABSTRACT

A tamping device which has a tamping foot and a mass above the foot in the form of a drive motor or engine and a crank driven thereby with a rod connected to the crank for being reciprocated thereby in the vertical direction and having a resilient connection with the tamping foot. The mass is also resiliently supported on the tamping foot and relative movement between the mass and the tamping foot is confined to a single vertical plane and within which plane the mass and tamping foot are moveable relatively in the vertical direction while the mass can be moved a certain amount laterally relative to the tamping foot in the plane or can be tilted in the plane whereby steering and movement of the device while in operation can readily be controlled by forces exerted manually on the mass.

United States Patent [191 Uebel et al.

[ TAMPING DEVICE FOR COMPACTING SOIL, CONCRETE, AND THE LIKE [75] Y Inventors: Philipp Uebel; Helmut I-Ieckner;

Dietrich Hoepfner, all of Munich, Germany [73] Assignee: Wacker-Werke KG, Munich,

Germany [22] Filed: Nov. 17, 1971 [21] App]. No.: 199,515

[30] Foreign Application Priority Data Nov. 25, 1970 Germany 2058038 [52] US. Cl. 404/133 [51] Int. Cl. E01c 19/38 [58] Field of Search 404/133, 113

[56] References Cited UNITED STATES PATENTS 3,270,635 9/1966 Kestel 404/133 3,308,729 3/1967 Kestel 404/133 3,283,677 11/1966 Uebel 404/133 X 3,492,924 2/1970 Fors et a1 404/133 FOREIGN PATENTS OR APPLICATIONS 4/1936 Great Britain 404/133 [451 Apr. 9, 1974 1,077,154 3/1960 Germany 404/133 483,904 8/1953 Italy 404/133 877,376 9/1961 Great Britain... 404/133 146,629 5/1952 Australia 404/133 23,871 10/1962 Germany Primary Examiner-Roy D. Frazier Assistant Examiner-Thomas J. Holko Attorney, Agent, or FirmWalter Becker [57 ABSTRACT A tamping device which has a tamping foot and a mass above the foot in the form of a drive motor or engine and a crank driven thereby with a rod connected to the crank for being reciprocated thereby in the vertical direction and having a resilient connection with the tamping foot. The mass is also resiliently supported on the tamping foot and relative movement be- "tween the mass and the tamping foot is confined to a single vertical plane and within which plane the mass and tamping foot are moveable relatively in the vertical direction while the mass can be moved a certain amount laterally relative to the tamping foot in the plane or can be tilted in the plane whereby steering and-movement of the device while in operation can readily be controlled by forces exerted manually on the massv 5 Claims, 5 Drawing Figures PATENTED P 9 I sneu 1 or 3 FIG-2 PATENTEDAPR 91914 SHEET 2 [If 3 FIG-3 20 0 zqa FIG-4 PATENTEDAPR- 9 m4 SHEET 3 BF 3 TAMPING DEVICE FOR COMPACTING SOIL, CONCRETE, AND THE LIKE The present invention relates to. a manually handled motor-driven tamping device for compacting soil, concrete, and the'like, which is provided with a tamping foot which by means of resilient coupling elements is coupled to a motor-driven crank drive on the upper mass. The device is furthermore provided with guiding means which prevent the tamping foot and the upper mass elastically resting with its entire mass on the tamping foot from a relative horizontal displacement in a direction perpendicular to the intended direction of movement of the tamping device.

Tamping devices of the just referred to type operate with a relatively low tamping frequency and with a relatively high oscillation amplitude of the tamping foot and in this respect differ from the so-called vibration plates which, as a rule, have the bottom plate acted upon by oscillation generators with rotating unbalance bodies and are oscillated at considerably higher fre-' quency and low amplitude. In view of their high oscillation amplitude with the oscillations extending substantially only in longitudinal direction, tamping devices of this general type can also be used for compacting wet and sticky soil.

Tamping devices of the above mentioned general type have a relatively great height. With such heretofore known tamping devices the problem of obtaining a sufficient stability and safety against tipping over during operation has to be taken into consideration by the fact that by correspondingly designing the guiding means between the tamping foot and the upper mass, relative movements are admitted exclusively in the form of a longitudinal movement in one direction, usually in the direction of the oscillation axis of the device, whereas the guiding direction of these parts is fixed in all other directions perpendicular thereto with regard to each other. The advancement in the desired direction ov movement is with heretofore known tamping devices realized by the fact that the device is with its oscillation axis on the tamping foot forwardly inclined in this direction which means that the oscillation axis confines with the tamping foot in this direction an angle of incidence which is less than 90 and generally is nonvariable. In view of this forward inclination in the desired direction of movement, the tamping foot is with each upward movement of the upper mass pulled forwardly to a slight extent whereby the device advances.

In view of the coupling between upper mass and tamping foot, the heretofore known tamping devices have already on a plane surface only a relatively low maximum speed of movement and cannot be guided as easily as is desirable because the operator cannot exert a delicate influence upon the character of movement of the tamping device. Moreover, the ability of the device to climb up an incline or slope is rather limited.

A further disadvantage of the heretofore known devices of the type involved consists in that during the impact upon the medium to be compacted the forces conveyed from the upper mass to the tamping foot include components of considerable magnitude in view of the inclination of the oscillation axis, which components act in a direction perpendicular to the oscillation axis and consequently exert a considerable load on the guiding means. The guiding means have, for this reason, to be designed rather sturdy and have to be equipped with wear-resistant bearings of high precision which requires considerable costs in material and labor.

It is, therefore, an object of the present invention to provide a device of the above mentioned general characterwhich will have greatly improved properties with respect to its advancement, its ability to be guided and its ability to climp up an incline, while the construction of such device will be simplified and will make such device more wear-resistant.

This object and other objectsand advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIG. 1 illustrates a first embodiment of a tamping device according to the invention and, more specifically, diagrammatically illustrates a section through the device taken along the line II of FIG. 2.

FIG. 2 shows a top view of thedevice according to FIG. 1.

FIG. 3 represents a second embodiment of a tamping device according to the invention and represents a section taken along the line III-III of FIG. 4.

FIG. 4 is a top view of FIG. 3.

FIG. 5 is a section similar to that of FIGS. 1 and 3 and illustrates a third embodiment of the tamping device according to the invention.

The tamping device according to the present invention for tamping soil, concrete, and the like with a tamping foot, which by means of resilient coupling elements with a motor-driven crank drive is coupled to the upper mass above the crank drive and is equipped with a guiding device which secures thetamping foot and the upper mass elastically resting with its entire weight on the tamping foot against-a relative horizontal displacement with regard to the desired direction of movement of the tamping device, is characterized primarily in that the guiding device permits relative movements between the upper mass and the tamping foot in the form of a pendulum movement parallel to the plane which is perpendicular to the desired direction of movementand to the tamping foot and inlthe form of a longitudinal displacement in said direction of movement, and is furthermore characterized in that elastic supporting members are providedbetween the upper mass and the tamping foot which supporting members act in adirection counter to said relative movements.

mass impacts. It is up to the operators discretion to control the pendulum movements in a fine way and to determine the angle at which the upper mass jumps up each time relative to the tamping foot in order to pull along the latter. As a result thereof, the operator is able delicately to guide the tamping device and also to permit the same to move over ascending slopes which with heretofore known tamping devices could not be mastered.

Inasmuch as the guiding device with the tamping device according to the invention is so designed that it permits the above described movements between upper mass and tamping foot, no forces can with any component act in the direction of movement. In view of the customary symmetric design of the device with regard to the vertical central plane extending in the direction of movement, no great forces will occur in a direction perpendicular to the direction of movement so that the guiding device is with regard to these forces likewise not exposed to any major loads or stresses. The guiding device can, therefore, structurally be of a simple design and is not. subjected to any major wear. Forces between upper mass and tamping foot which are caused by the advancing movement of the tamping device are completely absorbed by the elastic supporting elements between these parts which, for instance, may be in the form of spiral springs, rubber springs, or the like, and thus represent inexpensive and sturdystructural elements. I

The operator also has the possibility of operating the tamping device selectively in forward or rearward drive by inclining the oscillating axis of the device by lifting ordepressing the guiding yoke if desired by means of an auxiliary device relative to the tamping foot away from or toward the operator.

It is also possible to make the guiding device reversible in such a way that, with regard to the guiding yoke, the directions in which the coupling and uncoupling between. upper massand tamping foot become effective are variable in such a way that the device will relative to the guiding yoke carry out a lateral movement while the forward or rearward movement is blocked.

According to a preferred embodiment of the invention, the guiding yoke may be in the form of a rocker arm with a vertical oscillating plane extending in the desired directionof movement of the tamping device.

A single rocker or rocker arm will permit only a relatively slight longitudinal displacement between upper mass and tamping foot in the desired direction of movement. lf'the rocker, according to a further development of the invention, is designed as a double rocker, the

upper mass will be able to displace itself to a considerable extent relative to the tamping foot in the desired direction of movement within the range of its free movement made possible by the elastic supporting members. In the last mentioned instance the maximum speed of movement of the tamping device is considerably higher than in the first instance. The extent to which the longitudinal displacement between upper mass and tamping foot is permitted will depend on the respective desired tamping power and depth of action of the tamping device. In this respect the tamping device may, according to a further development of the invention, be made variable by equipping the device with a double rocker which has locking means for selectively converting the double rocker into a single rocker. According to a still further development of the invention, the guiding device may also consist of columns rigidly connected to the upper mass orto the tamping foot. These columns engage oblong holes provided on the tamping foot or the upper mass, the oblong holes extending in the desired direction of movement. Particularly with heavy tamping devices it is expedient to support the upper mass and the tamping foot relative to each other by means of the elastic supporting elements in the desired direction of movement of the tamping device at various points spaced from each other. These supporting points are preferably so selected that they are located in front of and behind the point of intersection of the axis of gravity of the upper mass with the tamping foot. The support of upper mass and tamping foot relative'to each other on more than one point results in a still greater stability of the device. In this instance also between the upper mass and the tamping foot there may be provided a device for varying the ratio of the elastic supporting forces effective in mutually spaced arrangement between these parts. The supporting forces permit the operator without any physical efforts to reverse the direction of movement and to control the speed of movement.

A further development of the invention finally consists in that the resilient coupling elements between crank drive and tamping foot simultaneously serve as elastic supporting means between the upper mass and the tamping foot. Inthis way afurther reduction in the necessary'structural elements will be obtained.

Referring now to the drawings in detail, the tamping device according to FlGS. l and 2 has an upper mass 1 which comprises a motor not illustrated in the drawing, for instance in. the form of an electric motor or an internal combustion engine, 7 and furthermore comprises a crank drive 2 adapted to be driven by said m0- .tor. The upper mass 1 is by means of elastic supporting elements 3, for instance helical springs, rested against the tamping foot 4 of the device. For purposes of simplification and clarification of the drawing, the tamping foot 4 is shown considerably larger than customary in practice. In the actual design the width of the device is relative to its height considerably less than shown.

The part 2a of the crank drive 2, which with this design is linearly reciprocable relative to the upper mass 1 in both directions of oscillation, is coupled to the tamping foot 4 by means of resilient coupling elements Between the tamping foot 4 and the upper mass 1 there is inserted a fork-shaped single rocker 6 which prevents the tamping foot 4 and the upper mass 1 from a relative displacement in a direction perpendicular to the desired direction of movement (see arrows 7 and 8), in other words in a direction perpendicular to the drawing plane, while however permitting relative movements between these parts in the form of a pendulum movement parallel to the plane which extends in the desired direction of movement and is perpendicular to the tamping foot, in other words, perpendicular to the drawing plane of FIG. 1 and in the form of a longitudinal displacement in this direction of movement. These movements of the upper mass 1 and tamping foot 4 with regard to each other are in FIG. 1 indicated by the arrows 9 and 10. A guiding yoke 11 engaging the upper mass 1 is provided for guiding the tamping device.

The supporting members 3 in this embodiment are arranged on four points spaced from each other and located symmetrically with regard to the longitudinal central axis of the device. These supporting members I 3 will in this arrangement impart a good stability upon the heavy upper mass 1 with regard to the tamping foot 4. The supporting members 3 counteract the possible movements which are left to the upper mass 1 and the tamping foot 4 with regard to each other by the rocker 6 and tend to align these elements in their position shown in FIG. 1. The transfer of the vibration forces onto the tamping foot 4 by the crank drive 2 acting as oscillation generator is effected approximately centrally by means of the resilient coupling elements 5 relative to the upper mass 1 and the tamping foot 4. It is at the operators discretion by lifting or pressing down the guiding yoke 11 to tilt the upper mass 1 relative to the tamping foot 4 away from or toward himself toward the rear to thereby operate the tamping device either in forward drive according to the arrow 7 or in rearward drive according to arrow 8. Depending on the magnitude of the tilting angle, the device will move faster or slower. A further factor which determines the forward or rearward speed is the extent of the linear displacement in the direction of the arrow between the upper mass 1 and the tamping foot 4 which linear displacement the rocker 6 allows these elements. In case of the single rocker according to the embodiment of FIGS. 1 and 2 this displacement is relatively limited so that also only a relatively low maximum advancing speed can be obtained. I

The advancing speed within this range from a standstill, i. e. tamping on the spot, to the maximum forward or rearward speed can be delicately controlled by the operator by a more or less strong lifting or lowering.

The design of the tamping device according to FIGS. 3 and 4 operates in conformity with the same basic principle as the design according to FIGS. 1 and 2. It differs therefrom merely in that instead of the single rocker 6, in this instance a double rocker with two rocking members 20a, 20b is provided which are pivotable relative to each other and are rigid in themselves. The members 20a, 20b permit a relative linear dis placement of upper mass 1 and tamping foot 4 in wide limits and to a considerably greater extent than the single rocker 6 of FIGS. 1 and 2. Consequently, the design of FIGS. 3 and 4 makes possible a considerably higher maximum forward and rearward speed of the tamping device than is possible with the tamping device of FIGS. 1 and 2.

If it is desired with the tamping device of FIGS. 3 and 4 to fix the maximum forward and rearward speed for a lower value than that which is obtainable with the double rocker 20, this can be realized in a simple manner by blocking the rocker members 20a and 20b against pivoting relative to each other by means of an arresting device, for instance, by means of pawl 21 shown in FIG. 3. In this way the double rocker 20 is converted into a single rocker which operates in the same manner as the rocker 6 of FIGS. 1 and 2. In this way it is also possible to build-in a speed change transmission.

With the embodiments according to FIGS. 1 to 4, the elastic supporting members 3 and the resilient coupling elements 5 form separate structural elements. In contrast thereto, FIG. 5 shows an embodiment in which these two functions are carried out by one and the same element. More specifically, according to FIG. 5, an oscillating plate 31 forming an intermediate mass is linked to a connecting rod 32 of the crank drive by means of which it can be oscillated relative to the upper mass 1. The oscillating plate 31 is by means of a cylinder piston guiding system 30 movable in vertical direction only parallel to the drawing plane. The oscillating plate 31 has, for instance similar to the'supporting members 3 of FIGS. 1 to 4, wide passage bores 32 through which the supporting columns 33 rigidly connected to the tamping foot 4 extend with their heads 33a. Between the heads 33a of the supporting columns and the oscillating plate 31 on one hand and between these elements and the tamping foot 4 on the other hand there are respectively interposed resilient elements 34 for instance helical springs, which simultaneously serve as resilient coupling elements between the crank drive and the taming foot and also as supporting members for supporting the upper mass 1 and the tamping foot 4.

Similar to the embodiments of FIGS. 1 to 4, also with the embodiment of FIG. 5, the upper mass 1 is by means of a double rocker 20' (which by means of a pawl or the like 21 can be converted into a single rocker) prevented from a relative displacement with regard to the tamping foot 4 in a direction perpendicuiar to the drawing plane which means perpendicular with regard to the desired direction of movement according to the arrows 7 and 8. This double rocker 20 is, in contradistinction to the embodiments of FIGS. 1 to 4, not directly linked to the upper mass 1 but instead to the oscillating plate 31.

With all embodiments described above, the guiding of the device by the operator may further be facilitated by means of a device which is operable by the operator and which will make itpossible for the operator to' change the ratio of the supporting forces which with these embodiments become effective at mutually spaced points on both sides of the line of gravity of the device. More specifically, this change in the supporting forces may be effected by increasing or decreasing an elastic force Pe acting in a direction parallel to the supporting members 34. Tile operator can, therefore, obtain the same result as'described above by depressing or lifting the guiding yoke 11'. Such an arrangement is diagrammatically shown in FIG. 5.

As will be seen from the above, with the above outlined tamping devices also a lateral movement of the respective device with regard to its guiding yoke 11, 11, in other words a movement perpendicular to the drawing plane, is obtainable when the respective rocker is turned by and is interposed between the upper mass and the tamping foot. A desired direction of movement will in such an instance be the normal to the drawing plane. It will thus be obvious that also tamping devices may be built in conformity with the principle of the present invention which advance not only forwardly and rearwardly but which can also operate in other directions of movement when the guiding device is reversible or shiftable. As an example there may be mentioned the employment of two single or double rockers of which one will respectively be turned off while the other is in operation and vice versa.

With the embodiment of FIG. 5, the rocker 20' may be omitted when the bores 32 are designed as oblong holes extending in the desired direction of movement and have a width which corresponds to the diameter of the supporting columns 33. In such an instance the same possibilities of relative movement would be obtained for the upper mass and the tamping foot which are also possible with the double rocker 20.

It is, of course, to be understood that the present invention is, by no means, limited to the particular showing in the drawings but also comprises any modifications within the scope of the appended claims.

What is claimed is:

1. In a tampingdevice for compacting materials such as concrete and soil; a tamping foot engageable with the material to be composited, a mass above the tamping foot including a motor and a crank driven thereby, a rod connected to said crank to be reciprocated by the crank and extending vertically downwardly therefrom toward said tamping foot, guide means operatively interposed between said mass to said tamping foot and permitting relative movement therebetween in only a single vertical plane, resilient means resiliently supporting said mass on said tamping foot and connecting said rod to said tamping foot, and graspable means connected to said mass for manual movement thereof in said plane in a direction transverse to the direction of reciprocation of said rod, said guide means comprising rocker means pivoted to said tamping foot and to said mass on respective axes parallel to each other and perpendicular to said plane, said rocker means comprising first and second rigid members, said first member having one end portion pivoted to said tamping foot and said second member having one end pivoted to said mass, the other ends of said first and second members being pivotally interconnected on an axis parallel to said axes at said one ends of said first and second members, and means for locking said first and second members together at the said other ends thereof to cause said first and second members to form a rigid unit.

2. A tamping device according to claim 1 which includes means for adjusting said resilient means resiliently supporting said mass.

3. A tamping device according to claim 1 which includes means for adjustably biasing said first and second members for relative rotation thereof about the pivotal interconnection of the said other ends thereof to adjust said resilient means resiliently supporting said mass.

4. A tamping device according to claim 1 in which said guide means includes posts fixed to said tamping foot and extending upwardly therefrom; a plate connected to said rod guided on said mass for reciprocation thereon parallel to the axis of said rod, and apertures in said plate through which said posts slidably extend and the apertures being elongated in a direction parallel to said plane.

5. A tamping device according to claim 4 in which said resilient means comprise first springs bearing between the bottom of said plate and the top of said tamping foot and second springs bearing between the top of said plate and the upper ends of said posts. 

1. In a tamping device for compacting materials such as concrete and soil; a tamping foot engageable with the material to be composited, a mass above the tamping foot including a motor and a crank driven thereby, a rod connected to said crank to be reciprocated by the crank and extending vertically downwardly therefrom toward said tamping foot, guide means operatively interposed between said mass to said tamping foot and permitting relative movement therebetween in only a single vertical plane, resilient means resiliently supporting said mass on said tamping foot and connecting said rod to said tamping foot, and graspable means connected to said mass for manual movement thereof in said plane in a direction transverse to the direction of reciprocation of said rod, said guide means comprising rocker means pivoted to said tamping foot and to said mass on respective axes parallel to each other and perpendicular to said plane, said rocker means comprising first and second rigid members, said first member having one end portion pivoted to said tamping foot and said second member having one end pivoted to said mass, the other ends of said first and second members being pivotally interconnected on an axis parallel to said axes at said one ends of said first and second members, and means for locking said first and second members together at the said other ends thereof to cause said first and second members to form a rigid unit.
 2. A tamping device according to claim 1 which includes means for adjusting said resilient means resiliently supporting said mass.
 3. A tamping device according to claim 1 which includes means for adjustably biasing said first and second members for relative rotation thereof about the pivotal interconnection of the said other ends thereof to adjust said resilient means resiliently supporting said mass.
 4. A tamping device according to claim 1 in which said guide means includes posts fixed to said tamping foot and extending upwardly therefrom, a plate connected to said rod guided on said mass for reciprocation thereon parallel to the axis of said rod, and apertures in said plate through which said posts slidably extend and the apertures being elongated in a direction parallel to said plane.
 5. A tamping device according to claim 4 in which said resilient means comprise first springs bearing between the bottom of said plate and the top of said tamping foot and second springs bearing between the top of said plate and the upper ends of said posts. 